Direct synthesis of benzoxazinones via Cp*Co(Ⅲ)-catalyzed C-H activation and annulation of sulfoxonium ylides with dioxazolones

A highly novel and direct synthesis of benzoxazinones was developed via Cp*Co(Ⅲ)-catalyzed C-H activation and[3+3]annulation between sulfoxonium ylides and dioxazolones.The reaction is conducted under base-free conditions and tolerates various functional groups.Starting from diverse readily available sulfoxonium ylides and dioxazolones,a variety of benzoxazinones could be synthesized in one step in 32%-75%yields.